activist vs militant

activist and militant both are nouns.

Word	Noun	Adjective	Verb	Adverb
activist	Yes	Yes	No	No
militant	Yes	Yes	No	No

As nouns, activist and militant are synonyms defined as:

activist (noun)	militant (noun)
a militant reformer	a militant reformer

activist (adjective)	militant (adjective)
advocating or engaged in activism	showing a fighting disposition
	disposed to warfare or hard-line policies
	engaged in war